Acoustic receiver array assembly

Abstract

An acoustic receiver array assembly includes an underwater vehicle having aase portion and an acoustic receiver portion. The base portion is provided with a rigid boundary wall defining a first largest diameter. The receiver portion is provided with a flexible boundary wall expandable from a generally cylindrical configuration of no more than the first diameter to an expanded configuration of a second diameter substantially larger than the first diameter, the receiver portion defining a chamber. Expansion means is disposed in the chamber and is operable to expand the receiver portion boundary wall to the second diameter. Acoustic receivers are mounted in the receiver portion and provide an acoustic receiver array which expands commensurately with the expansion of the receiver portion boundary wall.

What is claimed is: 
     
       1. An acoustic receiver array-assembly, said assembly comprising: an underwater vehicle having a base portion and an acoustic receiver portion, said base portion having a rigid boundary wall of a configuration defining a first diameter, said receiver portion having a flexible boundary wall expandable from a generally cylindrical configuration of no more than said first diameter to an expanded configuration of a second diameter substantially larger than said first diameter, said receiver portion defining a chamber;   expansion means disposed in said chamber and operable to expand said receiver portion boundary wall to said second diameter; and   acoustic receivers positioned in said receiver portion and providing an acoustic receiver array which expands commensurately with said expansion of said receiver portion boundary wall.   
     
     
       2. The assembly in accordance with claim 1 wherein said expansion means comprises: a central post assembly extending axially through said chamber;   arms disposed in said chamber and pivotally connected at a first end to said central post assembly;   struts, each pivotally mounted at a first end on said central post and at a second end pivotally fixed to one of said arms;   means for moving said arm first ends axially along said central post to cause said arms to move from a first position generally adjacent said central post to a second position wherein said arms extend outwardly from said central post to cause said struts to move from a first position generally adjacent said central post to a second position wherein said struts extend outwardly from said central post, said struts bearing against said flexible boundary wall to expand said flexible boundary wall; and   wherein said acoustic receivers are mounted on a selected one of said flexible boundary wall and said arms.   
     
     
       3. The assembly in accordance with claim 2, further comprising: a nose portion;   said arm first ends being pivotally mounted proximate said nose portion; and   a plunger slidable in said central post and fixed to said nose portion to slide said nose portion reciprocally of said central post.   
     
     
       4. The assembly in accordance with claim 3 wherein said plunger is joined to a linear actuator to cause said nose portion to slide reciprocally with respect to said central post. 
     
     
       5. The assembly in accordance with claim 2, further comprising a valve for admitting liquid into said chamber. 
     
     
       6. The assembly in accordance with claim 2 wherein a plurality of said acoustic receivers are mounted on each of said arms. 
     
     
       7. The assembly in accordance with claim 1 wherein said expansion means comprises a valve for admitting liquid into said chamber to cause said flexible boundary wall to expand, and wherein said acoustic receivers are mounted on said flexible boundary wall.